Orbiting space stations have progressed in two stages. Initially, orbiting space stations were designed so that they could be placed in orbit in unitary form and sent aloft in one space shot and expanded or otherwise modified during deployment into operational configuration. These space stations were generally toroidal in form. U.S. Pat. Nos. 3,144,219, 3,169,725, and 3,332,640 are exemplary of that earlier approach.
U.S. Pat. No. 3,169,725 involves a high hybrid inflatable body/rigid body construction with rigid cylindrical sections joined by flexible connectors with the sections connected to a central hub and erectable to form a rigid, hexagonal, tubular ring thereabout, upon reaching the desired orbit.
U.S. Pat. No. 3,326,640 involves a partly preconnected structure utilizing cylindrical sections which are hinged to each other such that upon reaching space, the segments which are clustered closely about the rocket carrier on launching, may be extended and joined together to form a toroidal structure.
With the advent of the Space Transportation System Shuttle Launch Vehicle (STS), the sections or components of the station are transported into orbit in incremental stages constrained by the cargo bay configuration and weight limitations associated with the STS shuttle. Under such conditions, the incremental parts of the station are then assembled in space into a functional space station assembly. Attempts have been made to create an acceptable space vehicle module to be joined in space at a predetermined earth orbit by a number of other space vehicle modules and to be connected together to form a pressure tight space station which is sufficiently large and provisioned to support a research or construction crew for extended periods of time.
U.S. Pat. No. 4,057,207 is directed to such a concept which is based on an earlier U.S. Pat. No. 3,953,948 permitting the resulting space station structure to conform to selected shapes possible in homohedral geometry; namely, two types of rings and four varieties of helicies. Structurally, each model consists of at least two joined, truncated icosahedra, the truncations occurring where up to three pentangular pyramids about nonadjacent vertices have been removed from each icosahedra; the connection occurring between two truncation surfaces, one from each icosahedra. In the system, the end truncation surfaces have alignment and docking means so that they can be brought to rigid physical contact with other similar truncation surfaces on other modules in up to five difference positions.
The use of an icosahedra as the geometric basis limits the structural faces of the modules to being all flat plates which limits the modules to a strong, heavy structure to resist the internal pressurization required of the station and requires six configurations to build a completed structure. Obviously, this design is hardly weight efficient which is a primary criteria. Further, the configuration of the icosahedra is neither effectively nor efficiently matched to the cargo bay configuration of the STS shuttle. While docking ports are provided within one or more of the flat faces of the icosahedra module, the system requires another specialized module for access to the station interior. The modules fail to include provision for load paths to accommodate launch loads. Not only is the icosahedra concept complicated, but internal access with the space station structure is constrained by the relatively small size of the icosahedra units and the interior structural beams required in their manufacture. The concept of U.S. Pat. No, 4,057,207 does not permit easy accommodation of modules which are to be isolated from the general atmospheric circulation system of the station, makes no provision for accommodating elements such as air locks and the associated hyperbaric chambers and hangar areas for operational equipment such as manned maneuvering units, and makes no provision for accommodating logistics modules into the space station structure.
It is, therefore, one object of the present invention to provide an improved, interconnectable space station module which is of simplified construction, has high strength to weight ratio, is of cylindrical body form, purposely sized and configurated to fit within the cargo bay of a STS orbiter, which can be interconnected into a variety of patterns without need for dedicated interconnect modules, and which has access ports to the individual modules which are always available for use as EVA air locks, logistics modules docking, etc.